Practical effects of doubling Sodium Sulfite
I was just mixing some concentrate ID-78 as per Ian Grant's formula, and commited a small mistake. I was going to mix enough for 2L of concentrate (to be dilluted 1:7) when I realized that I only had enough Pot Carb for 1L. By then, I already had 200g of Sodium sulfite in the water (instead of the 100g the concentrate recipee calls for).
To make a long story short, I decided to mix 1L of concentrate, but with twice the amount of sulfite. In effect, the working developer went from 12.5g of Sodium Sulfite per liter to 25g per liter. What should I expect from such an increase?
I know that Sulfite is an antioxidant - will it the developer last any longer than the correct formula or did I just waste 100g of sulfite?
I'm also aware that at certain concentrations sulfite acts as a solvent - but isn't it mostly above the 100g per liter concentrations? Will the jump from 12.5g/L to 25g/L have a major effect in tonality (grain size in the paper)?
Mostly, I'm just curious if I wasted the extra sulfite or not. If I did, next batch will be normal.
As always, thank's in advance,
André de Avillez
You could substitute sodium carbonate - mono for potassium carbonate - anhy at a level of .90 sodium to potassium to fill out the two liter.
Thanks, but unfortunately I don't have any Sodium carbonate on hand either, which is why I had used Pot Carb instead. That's fixed now, as I've just placed an order for 8lbs of Sodium Carbonate and 10lbs of Sodium Sulfite (only had 200g left).
I don't think that anything bad will come out of doubling the sulfite concentration (it might make grains smaller = colder tone, but I doubt it). I'm hoping that it will lead to a longer tray life, but I think that worst case scenario nothing will happen.
I'd like to be able to dillute 4L of working solution, use it for a day, pour it in a bottle and use it again a few days later. Maybe 25g/L of Sulfite in a PQ developer will allow for that. I know that Diafine (a PQ developer as well), which in my experience has lasted a while, has 35g/L in bath A and 65g/L in bath B (some people have reported 35g/L with no adverse effects). Then and again, Diafine is not used in trays, so much less oxidation takes place.
Heck, I know that the only way to know is to test, but I'm always willing to sponge off of other's knowledge if it will save me some effort :rolleyes:...
Thank you for responding, and thanks for the advice.
You can get some pretty good sodium carbonate by looking for plain Washing Soda at the grocery store. You may have to make some mods due to a different hydrate content, I think it has more. That was covered in a previous thread.
Off Topic: sodium carb > washing soda
I've been using Arm & Hammer Washing Soda to replace sodium carbonate at a 1 to 1 ratio. I've come to understand the A&H is monohydrated in the store bought variety. Just be sure it does not contain any perfumes or "brighteners" and you won't know any difference. Been using it for over a year and haven't found a problem.
Originally Posted by glbeas
Sponsored Ad. (Subscribers to APUG have the option to remove this ad.)
Anyway, I just paid $11.60 (plus shipping) for 8lbs of Sodium Carbonate at the Chemisty Store http://www.chemistrystore.com/ Arm and Hammer might be cheaper due to the shipping and handling I paid (a little less than 19 bucks, but then I did buy 10lbs of sulfite as well).
BTW, don't worry about the off topic thing. Converstations go off topic in the real world, don't they?
I'm betting that the most apparent effect of the added sulfite will be increased developer activity. Try cutting development time by 30 percent.
Doubling sulfite you say?
I think that should have an effect on the ativity of the developer (faster), as well as some effect on the highlights and the grain of the paper (solvency)
The antioxidant effect will be higher and the dev should keep well.
Mama took my APX away.....
Another interesting thing, I found sodium sulfite and a few other chems in the pool supplies at Wally World, and on a whim looking in a pool supply store more of the same. Odd thing is what we were looking for, sodium thiosulfate, was nowhere in sight. I've read quite often pool supply houses carry this. Seems it's function was replaced by an organic compound.
Thank you, psvensson and tritisol. I might print a little bit tomorrow, so I'll find out how the developer works out.
Gary, I would never have guessed that walmart could cater to our chemical needs... But then can you tell if their sulfite is anihydrous, etc...?
Which brings up this: I'm sure I read somewhere that the Chemistry Store's sulfite was anihydrous, but couldn't find it on their site.... I guess I'll find out when it gets here (if it's labeled).